The conversion of (+)-dehydroabietic acid into steroidal hormones

A resin acid, (+)-dehydroabietic acid, was converted into 3,4,4a,9,10,10a-hexahydro-7-methoxy-10aβ-methyl-4aαH-phenanthren-1(2H)-one (2) by the introduction of oxygen functions at the C-4 and C-13 positions, and a rearrangement of the angular methyl group to the C-5 position. The hydrophenanthrene derivative 2 was further transformed into 2,3,3a,4,5,9b-hexahydro-7-methoxy-3aβ-methyl-9bαH-1H-benz[e]inden-3β-ol (3). Since the conversion of 3 into steroidal hormones has already been reported, the present synthesis can be regarded as the synthesis of steroidal hormones from (+)-dehydroabietic acid.